1. Field of the Invention
The present invention relates to a plug-in unit consisting of a sub-rack constituting electronic equipment such as communication equipment and related structure and a printed circuit board including electronic circuit parts inserted into and removed from the sub-rack. for inserting the plug-in unit into the sub-rack and removing the plug-in unit from the sub-rack.
2. Description of the Prior Art
FIG. 1 is a perspective view of the constitution of a conventional sub-rack. In FIG. 1, reference numeral 100 denotes a sub-rack while 101 denotes a top plate, 102 denotes a bottom plate, 103 denotes a side plate and 104 denotes a front rail arranged on front edges of the top plate 101 and the bottom plate 102, respectively. Reference number 105 denotes a mid-rail arranged on a midrange of the top plate 101 and the bottom plate 102, respectively, so as to cross the midrange while 106 denotes a guide rail whose opposite ends are mounted on upper faces of the front rail 104 and the mid-rail 105 and 107 denotes a locating hole used for locating a position on which a plug-in unit (not shown) is inserted.
FIG. 2 is a perspective view of the sub-rack 100 that a plug-in unit is partially mounted. In FIG. 2, 111 denotes a front panel for covering an opening of the sub-rack 100 when the plug-in unit is housed in the sub-rack 100 while 112 denotes a handle arranged on the front panel 111, the handle 112 being used for insertion and removal of the plug-in unit. Reference number 112a denotes a lever part being operated on operating rotationally the handle 112. FIG. 3 is a side view of the constitution of a plug-in unit inserted into the sub-rack. In FIG. 3, reference number 120 denotes a plug-in unit, 121 denotes a printed circuit board constituting the plug-in unit, and 122 denotes a connector arranged on the printed circuit board 121, which can be connected to a connector arranged on a back plane by a plug-in mode. Reference number 123 denotes a guide pin, which is inserted into a locating hole 107 in order to locate the front panel 111, 124 denotes a handle-support part, which is coupled to the printed circuit board 121 or the front panel 111 and 125 denotes a pin, which is locked to the handle 112 or the handle-support part 124 to allow the rotation of the handle 112 with respect to the handle-support part 124. In FIG. 3, since common numerals denote common elements in FIG. 2, the description of such parts is omitted.
FIG. 4 is a side view of a conventional insertion and removal system in a plug-in unit for inserting the plug-in unit into the sub-rack and removing the plug-in unit from the sub-rack. In FIG. 4, reference number 131 denotes a first engagement claw formed on the handle 112 and 132 denotes a second engagement claw formed on the handle 112. Reference number 133 denotes a first engagement part formed on the front rail 104 and 134 denotes a second engagement part formed on the front rail 104. In FIG. 4, since the common numerals denote common elements in FIGS. 1 to 3, the description of such parts is omitted.
The motion will be described as follows:
When the plug-in unit 120 having the printed circuit board 121 is inserted into the sub-rack 100, the printed circuit board 121 is slid along a groove formed on the guide rail 106. The guide pin 123, arranged on the plug-in unit 120, is then inserted into the locating hole 107 formed in the front rail 104 to locate the front panel 111 with respect to the front rail 104. The lever part 112a of the handle 112 is then rotated in a direction of arrow A shown in FIG. 4 in a state of engaging the first engagement claw 131 of the handle 112 with the first engagement part 133 of the front rail 104. The connector 122 of the printed circuit board 121 is connected to the back plane to finish the insertion of the plug-in unit 120.
When the plug-in unit 120 is removed from the sub-rack 100, the lever part 112a of the handle 112 is rotated in a direction of arrow B shown in FIG. 4 in a state of engaging the second engagement claw 132 of the handle 112 with the second engagement part 134 of the front rail 104 to disconnect the connector 122 of the printed circuit board 121 from the back plane. The printed circuit board 121 is pulled along the groove formed on the guide rail 106 to remove the plug-in unit 120 from the sub-rack 100.
With such an arrangement of the insertion and removal system in the plug-in unit, the length of the lever part 112a of the handle 112 cannot be changed. Consequently, it is not possible to provide a sufficient force for insertion and removal according to the plug-in unit with the necessary insertion and removal force, as the trend toward more and more pins on a connector.
In the case that the lever part 112a of the handle 112 is increased in length to be compatible with the plug-in unit with the need of the insertion and removal force, an area mounted on the front panel 111 is narrowed because of the long lever part 112a. 
In the case that the lever part 112a of the handle 112 is carelessly rotated in the direction of arrow B shown in FIG. 4 in a state of fitting the plug-in unit 120 in the sub-rack 100, there is a possibility that the plug-in unit 120 is accidentally removed from the sub-rack 100.
JP-A-2000/91770 discloses an insertion and removal system in a plug-in unit for resolving such problems above.
FIG. 5 is a side view of the constitution of a conventional insertion and removal system (hereafter, referring to a conventional example 1) in a plug-in unit as disclosed in JPA-2000/91770. In FIG. 5, 221 denotes a tool for insertion and removal system in a plug-in unit. Reference number 222 denotes a lever part rotationally operated on insertion and removal of the plug-in unit with respect to the sub-rack and 222A denotes a slider constituting the lever 222, which is inserted into a tubular part 223A of a main body 223. Reference number 222B denotes an action part for insertion and removal of the lever 222, which is acted upon by a rotational force when rotationally operating. Reference number 223 denotes a main body having a tubular part 223A which allows insertion of the slider 222A of the lever 222 while 223AA denotes a first engagement part arranged on the main body 223, and 223BA denotes a second engagement part arranged on the main body 223. Reference number 228 denotes a central hole which allows insertion of a pin 241 for rotating a construction part, including the lever 222 and the main body 223, in an insertion or removal direction. Reference number 231 denotes a printed circuit board constituting the plug-in unit and 233 denotes a vertical piece formed on a portion, on which the tool 221 is placed, at a right angle.
Operation of this invention will be explained as follows when the plug-in unit having the printed circuit board 231 is inserted into the sub-rack, the printed circuit board 231 is slid in the direction of arrow 251 along a groove formed on the guide rail. The slider 222A is slid from the tubular part 223A of the main body 223 in an extension direction of the length of the lever 222. The action part 222B of the lever 222 in the tool 221 is rotated in a direction of arrow 252 about a rotational axis including the central hole 228 and the pin 241. Here, the second engagement part 223BA of the main body 223 is engaged with the vertical piece 233 of the sub-rack to transfer such a rotational force as a force in a direction of arrow 251 to the printed circuit board 231. As a result, the printed circuit board 231 of the plug-in unit is moved in the direction of arrow 251 to insert the plug-in unit into the sub-rack.
When the slider 222A is downwardly slid in a state of rotationally moving the lever 222 toward the printed circuit board 231, the slider 222A is ejected from a lower end of the tubular part 223A. The ejected slider 222A comes into contact with one side of the vertical piece 233 having the other opposite side where the printed circuit board 231 is arranged. As a result, the rotation of the tool 221 is locked. Up to this point, the insertion motion of the plug-in unit is finished.
When the plug-in unit is removed from the sub-rack, the slider 222A is slid from the tubular part 223A of the main body 223 in an extension direction of the length of the lever 222. The action part 222B of the lever 222 in the tool 221 is rotated in a direction of arrow 253 about a rotational axis including the central hole 228 and the pin 241. Here, the first engagement part 223AA of the main body 223 is engaged with the vertical piece 233 of the sub-rack to transfer such a rotational force as a force in a direction of arrow 254 to the printed circuit board 231. As a result, the printed circuit board 231 of the plug-in unit is moved in the direction of arrow 254 to remove the plug-in unit from the sub-rack.
Thus, the length of the lever part can be changed by sliding the slider 222A in the tubular part 223A of the main body 223. Consequently, a sufficient force for insertion and removal according to the plug-in unit can be provided, as the trend toward more and more pins on a connector continues. The area, mounted on the front panel, is not narrowed because the lever 222 is changeable in length.
Another system is disclosed in JP-U-6/21273. FIG. 6 is a side view of the constitution of a conventional insertion and removal system (hereafter, referring to a conventional example 2) in a plug-in unit as disclosed in JP-U-6/21273. In FIG. 6, reference number 302 denotes an extension lever part of engaging with an operation part 321a of a lever 321 to substantially extend the length of the lever 321 while 303 denotes a mounting part for mounting the lever 321 on a lower portion of a front end of the printed circuit board 310. Reference number 303b denotes a rotational axis for rotating the lever 321 in an insertion or removal direction of the plug-in unit while 304 denotes a first engagement claw arranged on the mounting part 303 and 305 denotes a second engagement claw arranged on the mounting part 303. Reference number 310 denotes a printed circuit board constituting the plug-in unit while 311 denotes a front rail arranged on a front end of the sub-rack, and 311a denotes an engagement part arranged on the front rail 311. Reference number 321 denotes a lever part including the mounting part 303, the operation part 321a and the extension lever 302 while 321a denotes the operation part used for inserting freely the extension lever 302 in an advance or retreat direction.
The operation of this invention will be described as follows:
When the plug-in unit having the printed circuit board 310 is inserted into the sub-rack, the printed circuit board 310 is slid along a groove formed on the guide rail. The extension lever 302 is slid on the operation part 321a in an extension direction of the length of the lever 321 to rotate the extension lever 302 in an insertion direction of the plug-in unit about the rotational axis 303b. Here, the first engagement part 304 of the mounting part 303 is engaged with the engagement part 311a of the front rail 311 to transfer such a rotational force as a force in the insertion direction to the printed circuit board 310. As a result, the printed circuit board 310 is moved in the insertion direction of the plug-in unit to be inserted into the sub-rack.
The extension lever 302 is then slid on the operation part 321a in an opposite direction of arrow B shown in FIG. 6. An end of the extension lever 302 on the side of the printed circuit board 310 is moved to inside of a circle having a radius, which is defined by a length R between the mounting part 303 and a comer of the printed circuit board 310. As a result, the end of the extension lever 302 on the side of the printed circuit board 310 comes into contact with the mounting part 303 and the comer of the printed circuit board 310. Rotation of the lever 321 is thus prevented. Up to this point, the insertion motion of the plug-in unit is finished.
When the plug-in unit is removed from the sub-rack, the extension lever 302 is slid on the operation part 321a in the extension direction of the length of the lever 321 to rotate the extension lever 302 in a removal direction of the plug-in unit about the rotational axis 303b. Here, the second engagement part 305 of the mounting part 303 is engaged with the engagement part 311a of the front rail 311 to transfer such a rotational force as a force in the removal direction to the printed circuit board 310. As a result, the printed circuit board 310 is moved in the removal direction of the plug-in unit to be removed from the sub-rack.
With such an arrangement, the conventional example 2 can obtain the same effects as the conventional example 1. With the conventional example 2, the rotation of the lever 321 is locked when the extension lever 302 is pushed down to a shrinkage position to prevent the plug-in unit from accidental removal out of the sub-rack.
With the conventional example 1, the slider 222A is ejected from the lower end of the tubular part 223A, and the ejected slider 222A comes into contact with one side of the vertical piece 233 having the other opposite side where the printed circuit board 231 is arranged. As a result, rotation of the tool 221 is prevented. A locking system must be therefore arranged beneath a rotational fulcrum of the tool 221, and the insertion and removal system on the periphery of an opening of the sub-rack is unavoidably increased in size to limit a downsizing of such system.
With the conventional example 2, the end of the extension lever 302 on the side of the printed circuit board 310 is moved to inside of a circle having a radius defined by the length R between the mounting part 303 and a comer of the printed circuit board 310. Accordingly, rotation of the lever 321 is prevented. As a result, the contact part of the extension lever 302 with the printed circuit board 310 must be arranged to be close to the rotational axis 303b in principle. When an external force is slightly acted on the lever part 302 on locking, a large force is acted on the contact part to facilitate breakage of the contact part.
If high-accuracy finish of an end face of the printed circuit board 310 and high-relative positional accuracy of the printed circuit board 310 to the rotational axis 303b are obtained, locking functions cannot be performed.
Accordingly, it is an object of the present invention to provide an insertion and removal system in a plug-in unit as follows:
The system includes a lever part substantially changeable in length so as to provide a sufficient insertion and removal force according to the plug-in unit with the need of the insertion and removal force.
The system includes a lever part, which can be shrunk after placing the plug-in unit in the sub-rack to prevent an area mounted on a front panel from narrowing.
The system does not allow breakage thereof on which external forces are exerted.
The system does not require high accuracy for manufacture of the plug-in unit.
The system includes a locking system, which does not limit to scale down it.
In order to achieve the object of the present invention, an insertion and removal system in a plug-in unit comprises a front panel arranged on a plug-in unit inserted into a sub-rack, the front panel covering an opening frame of the sub-rack when the plug-in unit is inserted into the sub-rack; a handle element including a lever part rotationally supported on an end of the front panel and rotationally operated in a direction of insertion or removal of the plug-in unit with respect to the sub-rack, and an engagement part engaging with a projection arranged on the opening frame of the sub-rack to transfer a rotational force worked on rotationally operating the lever part to the projection, as a force for acting in the insertion or removal direction; a handle-extension slide element inserted freely into the lever part in an advance or retreat direction to be slid in a longitudinal direction of the lever between an extension position of the lever on extending the lever at the maximum and a shrinkage or retracted position of the lever whose length nearly corresponds to the length of the lever; and a locking element arranged on the handle-extension slide element and the front panel, the locking element for locking the handle-extension slide element being slidable to the shrinkage or retracted position on the front panel.
Here, the locking element may include a pit arranged in the handle-extension slide element and a projection arranged on the front panel for mating with the pit, and the handle-extension slide element maybe locked by mating the projection with the pit when the handle-extension slide element is slid to the shrinkage position.
The handle-extension slide element may have a pit arranged in the front panel. A detector may further include a detector for detecting an insertion or removal state of the plug-in unit with respect to the sub-rack, with linking to a locking motion and an unlocking motion of the locking element with respect to the handle-extension slide element or the lever element.
An insertion and removal system in plug-in unit comprises a front panel arranged on a plug-in unit inserted into a sub-rack, the front panel for covering an opening frame of the sub-rack when the plug-in unit is inserted into the sub-rack; a handle element including a lever part rotationally supported on an end of the front panel and rotationally operated in a direction of insertion or removal of the plug-in unit with respect to the sub-rack, and an engagement part engaging with a projection arranged on the opening frame of the sub-rack to transfer a rotational force worked on rotationally operating the lever part to the projection, as a force in the insertion or removal direction; a handle-extension slide element inserted freely into the lever part in an advance or retreat direction to be slid in a longitudinal direction of the lever between an extension position of the lever on extending the lever at the maximum and a shrinkage position of the lever part whose length nearly corresponds to the length of the lever part; and a locking element including an engagement pit arranged in the lever part and an engagement projection arranged on the front panel, the engagement projection engaging with the engagement pit when the lever part is rotated toward the front panel side, for locking the lever part on the front panel by transferring a stress generated in the lever part to the engagement pit as a force narrowing an opening diameter of the engagement pit to lock the lever part on the front panel.
Here, a detector may be arranged on an outer peripheral portion of the engagement projection, the detector detecting a normal finish of the engagement motion with respect to the engagement pit.
The handle-extension slide element may have a pit arranged in the front panel.
The detector may further comprise a detector for detecting an insertion or removal state of the plug-in unit with respect to the sub-rack, with linking to a locking motion and an unlocking motion of the locking element with respect to the handle-extension slide element or the lever part.
An insertion and removal system in plug-in unit comprises a front panel arranged on a plug-in unit inserted into a sub-rack, the front panel for covering an opening frame of the sub-rack when the plug-in unit is inserted into the sub-rack; a handle element including a lever part rotationally supported on an end of the front panel and rotationally operated in a direction of insertion or removal of the plug-in unit with respect to the sub-rack, and an engagement part engaging with a projection arranged on the opening frame of the sub-rack to transfer a rotational force worked on rotationally operating the lever part to the projection, as a force in the insertion or removal direction; a handle-extension rotation element rotationally supported on the lever part to rotationally move in a longitudinal direction of the lever part between an extension position of the lever part on extending the lever part at the maximum and a refractive position of the lever part whose length nearly corresponds to the length of the lever part; and a locking element arranged on the handle-extension rotation element and the front panel, the locking element for locking the handle-extension rotation element, rotationally moved to the refractive position, on the front panel.
Here, the handle-extension rotation element may include an axial part rotationally supported on the lever part and a plate part of connecting with the axial part, the handle-extension rotation element in the extension position has a planar shape.
The locking element may include a projection, which is arranged in the handle-extension rotation element, and a pit, which is arranged in the front panel for mating with the projection, and wherein the handle-extension rotation element is locked by mating the projection with the pit when the handle-extension rotation element is rotationally moved to the refractive position.
The handle-extension rotation element may include an axial part rotationally supported by the lever part and a plate part of connecting with the axial part, the handle-extension rotation element in the extension position has a planar shape.
The detector may further comprise a detector for detecting an insertion or removal state of the plug-in unit with respect to the sub-rack, with linking to a locking motion and an unlocking motion of the locking element with respect to the handle-extension rotation element.